hackbench regression due to commit 9dfc6e68bfe6e
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From: Eric Dumazet on 7 Apr 2010 14:40 Le mercredi 07 avril 2010 à 13:20 -0500, Christoph Lameter a écrit : > On Wed, 7 Apr 2010, Pekka Enberg wrote: > > > Oh, sorry, I think it's actually '____cacheline_aligned_in_smp' (with four > > underscores) for per-cpu data. Confusing... > > This does not particulary help to clarify the situation since we are > dealing with data that can either be allocated via the percpu allocator or > be statically present (kmalloc bootstrap situation). > > -- Do we have a user program to check actual L1 cache size of a machine ? I remember my HP blades have many BIOS options, I would like to make sure they are properly set. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Christoph Lameter on 7 Apr 2010 15:40 On Wed, 7 Apr 2010, Pekka Enberg wrote: > Yes, I am an idiot. :-) Plato said it in another way: "As for me, all I know is that I know nothing." -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Zhang, Yanmin on 7 Apr 2010 21:10 On Wed, 2010-04-07 at 20:38 +0200, Eric Dumazet wrote: > Le mercredi 07 avril 2010 � 13:20 -0500, Christoph Lameter a �crit : > > On Wed, 7 Apr 2010, Pekka Enberg wrote: > > > > > Oh, sorry, I think it's actually '____cacheline_aligned_in_smp' (with four > > > underscores) for per-cpu data. Confusing... > > > > This does not particulary help to clarify the situation since we are > > dealing with data that can either be allocated via the percpu allocator or > > be statically present (kmalloc bootstrap situation). > > > > -- > > Do we have a user program to check actual L1 cache size of a machine ? If there is no, it's easy to write it as kernel exports the cache stat by /sys/devices/system/cpu/cpuXXX/cache/indexXXX/ > > I remember my HP blades have many BIOS options, I would like to make > sure they are properly set. > > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Eric Dumazet on 8 Apr 2010 01:00 Le jeudi 08 avril 2010 à 09:05 +0800, Zhang, Yanmin a écrit : > > Do we have a user program to check actual L1 cache size of a machine ? > If there is no, it's easy to write it as kernel exports the cache stat by > /sys/devices/system/cpu/cpuXXX/cache/indexXXX/ Yes, this is what advertizes my L1 cache having 64bytes lines, but I would like to check that in practice, this is not 128bytes... ../index0/type:Data ../index0/level:1 ../index0/coherency_line_size:64 ../index0/physical_line_partition:1 ../index0/ways_of_associativity:8 ../index0/number_of_sets:64 ../index0/size:32K ../index0/shared_cpu_map:00000101 ../index0/shared_cpu_list:0,8 ../index1/type:Instruction ../index1/level:1 ../index1/coherency_line_size:64 ../index1/physical_line_partition:1 ../index1/ways_of_associativity:4 ../index1/number_of_sets:128 ../index1/size:32K ../index1/shared_cpu_map:00000101 ../index1/shared_cpu_list:0,8 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Eric Dumazet on 8 Apr 2010 01:40
I suspect NUMA is completely out of order on current kernel, or my Nehalem machine NUMA support is a joke # numactl --hardware available: 2 nodes (0-1) node 0 size: 3071 MB node 0 free: 2637 MB node 1 size: 3062 MB node 1 free: 2909 MB # cat try.sh hackbench 50 process 5000 numactl --cpubind=0 --membind=0 hackbench 25 process 5000 >RES0 & numactl --cpubind=1 --membind=1 hackbench 25 process 5000 >RES1 & wait echo node0 results cat RES0 echo node1 results cat RES1 numactl --cpubind=0 --membind=1 hackbench 25 process 5000 >RES0_1 & numactl --cpubind=1 --membind=0 hackbench 25 process 5000 >RES1_0 & wait echo node0 on mem1 results cat RES0_1 echo node1 on mem0 results cat RES1_0 # ./try.sh Running with 50*40 (== 2000) tasks. Time: 16.865 node0 results Running with 25*40 (== 1000) tasks. Time: 16.767 node1 results Running with 25*40 (== 1000) tasks. Time: 16.564 node0 on mem1 results Running with 25*40 (== 1000) tasks. Time: 16.814 node1 on mem0 results Running with 25*40 (== 1000) tasks. Time: 16.896 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |